The head of a Chicago-based company that manages physicians who make house calls and one of its most prolific doctors were arrested Tuesday on charges the company fraudulently billed Medicare for millions of dollars by inflating the level of care given patients. A criminal complaint charged Dike Ajiri, chief executive officer of Mobile Doctors, with health care fraud and Banio Koroma, a physician who has worked for the company since 2007, with making false statements. Federal agents raided Mobile Doctors' headquarters in the 3300 block of North Elston Avenue and branch offices in Detroit and Indianapolis and also sought to seize about $2.6 million in alleged fraudulent proceeds from various bank accounts, prosecutors said.